Variegated floor covering and method of making same



Dec. 9, 1930; c. ELLIS 1,784,804

VARIGATED FLOOR COVERING AND METHOD OF MAKING SAME Filed Dec. 5, 192

COLOR VAMEGATED TREAD. I

FLEX\BLE SHEET SUPPORT Qwuawto'z 'CRRLETON E LUS.

Patented Dec. 9, 1930 FF! C E GA R-LETON ELLIS, F MONTCLAIR, NEW JERSEY,ASSIGNOR '1'0 ELLIS-FOSTER COMPANY,

' A COR-PQRATION OF NEW JERSEY VARIEGATED FLOOR COVERING AND METHOD OFMAKING SAME Application filed December 3, 1926.

This invention relates to floor coverings containing a cellulose etheror ester as the primary or essential plastic and binding agent, andrelates particularly to floor coverings containing nitrocellulose.

The drawing shows a cross section through one form of a floor coveringmade in accordance with the present invention.

In the preferred form of the invention a plastic tread composition isapplied to a supporting Web or fabric. Such a support or backingpreferably paper or sheets of pulp material, but in some cases, and formore ex pensive products, cloth, burlap, and the like, may be utilized.

The paper material does not need .to be prepared from high gradeexpensive fibre, but may be made from ground wood, with perhaps someaddition of sulphite fibre, and the like, to add strength. Various cheapfibres may be employed since the paper backing is practically concealed,being in contact with the floor. The paper may be dyed in difierentcolors, if desired, so as to correspond in tone with that of the treadcomposition, or may be of any other shade. Preferably such paper isrendered water resistant. This does not mean that it is necessarilyabsolutely waterproofing, but a sufficient amount of a waterproofingagent, preferably is present. to preclude disintegration in case thefloor becomes wet or when the floor covering is used in a damp localitythat absorption of moisture will not cause any undue swelling of thepaper backing with consequent distortion or buckling.

In some cases asphalt-saturated paper of a grade known as felt may beemployed. This saturated felt is highly water resistant, but has thedisadvantage when white or delicately tinted floor coverings aredesired, of soiling the tread composition or throwing it ofi shade. Thisis due to small particles of Serial No. 152,520.

erings, I preferably do not employ a paper backing saturated with blackmaterials.

A suitable paper for backing purposes made from ground wood and sulphitepulp carries some rosin size to give strength and wax particlespreferably introduced into the paper by adding dispersions or emulsionsof paraffin wax or other waxes to the pulp in the beater engine. In thisway a wax-sized paper is obtained, which although containing but'a smallamount of wax, say from 1 to 5 per cent, is quite water resistant. Paperappropriate for the foregoing purpose is described in U. S. Patents Nos.1,607,517-8-9 and 1,607,- 552 all of November 16, 1926.

Thin paper preferably is used for the backing, and in order to avoidsplitting of laminations, enough rosin size or other binder should bepresent to cause the fibres to adhere tightly. Papers of the kraft typeare useful when waterp-roofed in the manner aforesaid. I prefer'to use athin paper-for several reasons. In the first place the paper itself doesnot afford any great amount of cushioning effect and I preferably relyon the tread composition applied to the paper to obtain such acushioning quality. In the second place a heavy paper, unless saturatedwith some material like asphalt or pitch, is prone toexpand when in amoist place and cause buckling. A paper which is only thick or stifienough to be passed through the sheeting rolls and, receive a layer oftread composition is satisfactory and does notintroduce anyobjectionable amount of paper stock into the product.

While I have thus stated the preferred form of the invention, I do notwish to be limited to the employment of such thin paper, but may usethick papers as occasion requires and may employ saturated felt asconditions warrant.

Preferably the paper has a rough texture or open surface, for example,showing marks of screens or felts employed in making the. paper,preferably being uncalendered or only lightly calendered and preferablybeingfree from oily substances or such a quantity of waxes as wouldserve to repel the nitrocellulose tread composition and prevent proper iadherence. It is important that thepaper backing does not at any timepeel away from the tread. Nitrocellulose does not adhere Well tosurfaces oiled with, for example, mineral oil.- It does not adhere .wellto a waxed surface, but by employing a wax .emulsion in makingthe-paper, but having the latter possess a fairly'rough surface,adequate adherence of the tread composition results.

The repellent effect of nitrocellulose on wax is recognized, and Ibelieve the employment by me of waxed paper to which a nitrocellulosecomposition will actually adhere constitutes a novel feature in thefloor covering industry.

A suitable paper may be made from ground wood-and sulphite p'ulp asaforesaid, having a thickness of about mm. and containing 2 or? per centof rosin size, and from 1 to 5 per cent of wax size.

The pa er may carry various fireproofing salts or su stances having afireproofing and waterproofing effect, as for example, bydrated calciumsulphate, some of the highly chlorinated compounds of benzol or naphthalene, chlorinated petroleum asphalt, and the like. Any substances togo into the paper for fireproofing or for other reasons should not havea harmful effect on nitrocellulose. For example, the latter is affectedby alkaline substances and therefore it is not desirable to have-anycondition of alkalinity which will have an objectionable effect on thenitrocellulose contacting with the paper surface.

As a floor covering should rest fiat on the floor and as thick paper isliable to curl, the employment not only of thin paper, but of paperimpregnated with substances which render it more flexible or pliable, orwhich absorb moisture and keep the paper from becoming bone drysometimes are desirable. Salts such as calcium chloride or magnesiumchloride are hygroscopic and also have some fireproofing qualities.Glycerine and glycol likewise may be employed for such special result.The paper-may be impregnated with resins which do not have anyobjectionable discoloring effect on the tread material and which affordmore waterproof products. In some cases certain vegetable oils, and thelike, maybe introduced into the paper structure.

The tread composition may be applied to thepaper backing in variousWays. but I prefer applying itowith the aid of sheeting rolls. These areof the type used in milling rubber and for calendering purposes.Preferably differential rolls are employed, that is, one roll runsslightly faster than the other. These sheeting rolls may be set to feedthe paper horizontally through them or their position may be altered sothe paper feeds vertic-ally down through the rolls or other angles offeed may be employed.

The composition employed for sheeting preferably is of a putty-likeconsistency, or

.tread' surface.

even slightly stiffer than putty. When a mass of it is squeezed in thehand preferably liquid should not exude nor should it stick very readilyto the hands. Preferably it should be as dry as i's-consistent withapplying it to the sheet of paper in a smooth layer. Such a putty-likeproduct when made according to the preferred form of the invention hasnitrocellulose as the primary cementing or binding agent, incorporatedwith plasticizer and filling material preferably of a fibrous character.

Antacid materials may also be present and in many cases I prefer toemploy a certain proportion of volatile solvent, as will be more fullyhereinafter set forth. 'The sheet of paper is'fed through the rolls andwhile it progresses the plastic tread material' is placed on the paper.before the rolls and as. paper and plastic pass therethrough,

the tread composition is squeezed tightly into contact with the paperand thus orms the Such tread surface may be further rolled or calenderedwhile still plastic to smooth the surface, or to disturb it in order togive texture, all depending on the character of the surface finishdesired.

In some cases it is possible to extrude a sheet of the tread compositionand permit'it to fall on a traveling sheet of paper, the. latter servingas a backing either temporary or permanent. In other cases, especiallywhen .a high proportion of binder is present, it-is possible toeliminate the paper backing entirely.

Floor coverings of the linoleum type as made today, have a smoothsurface. This gives a severe kitchen-like effect and limits theapplications of linoleum to a very considerable degree. On the otherhand, roughfinished textured effects would afford a type of floorcovering of muchgreater artistic possibilities than the harsh smooth andeven glossy surfaces of the present day linoleum, congoleum, and soforth.

A suitably textured floor covering may be made from nitrocellulose, aswill be hereinafter more fully described.

Light colored effects have an important field of application. A purewhite floor covering is desired because of its sanitary appearance.Rubber, boiled oils, and resins such 'as are employed in present dayfloor coverings make it diflicult to obtain a pure white. Usingnitrocellulose, it is possible to obtain a practically pure white tread.Having such a pure color, it is then possible to add various tints andobtain new effects, for example, soft green, rose, pastel shades, andthe like, which are not obtainable if the ground color is not purewhite. This, if coupled with the aforesaid textured efi'ect, enablesfloor rugs to be ance, may be used in the home, or in hospitals,

made, which because of their'artistic appearnr w) public buildings andthe likein a widespread manner.

The procedure therefore overcomes the kitchen-like severity of ordinarylinoleum and yields new decorative effects of great possibilities.

Having obtained a white or light-colored background it becomes possibleto introduce into the sheeting small masses of other and more intensecolors and thus obtain mottled or variegated color effects. This resultmay be obtained by adding small particles of colored tread compositionto the mass of the main tread composition as it is passing through thesheeting rolls. A better procedure is to sheet the main treadcomposition on the paper backing and as it emerges from the sheetingrolls to scatter small masses of colored tread composition over themoist surface and allow the sheet to pass through a second set of rolls,thereby rolling the colored masses into the tread and squeezing suchmasses over the surface to distribute them in a variegated manner. Thus.innumerable i'nulti-colored or polychrome efiects may be obtained.

If desired, instead of using two sets of rolls there may be a pluralityof rolls and different colored masses added between the different rolls,all while the light-colored ground mass of the tread is sufiicientlymoist and, Plastic.

Using a white ground, for example, and

adding small particles of green. plastic composition,

will give a'product with a white background and splotches or streaks ofgreen. in a similar manner white and rose, or white and blackcombinations may be secured.

The addition of such supplemental colors is not as well carried out on asingle set of rolls, that is, conducting the operation of sheeting andcoloring all on one set of rolls as by the use of auxiliary rolls. Thereis a greater tendency when using a single set of rolls in getting someof the coloring compositions so much mixed in with the main treadcomposition that the latter becomes simply discolored and the welldefined mottled effects desired are not produced in the samesatisfactory manner. Purity of the ground tone color is highly importantand the present invention makes it possible to secure technical resultsof the character specified through the availability of such pure groundcolored tread composition.

In some cases also it is proposed to extrude onto a light-colored treadcomposition tiny streams of composition of a stronger color and causethe sheeting to pass through a second set of rolls, whereby the extrudedmaterial is impressed into the main tread composition. This enablesstripes of color to be obtained. If the extruding tubes are given alateral movement while the sheeted material is fed forward, the stripeswill have an undulating character.

Again, it is possible to reverse the color effect and to apply lightercolored material in small proportion to a dark pigment.

. In making the plastic composition I may employ nitrocellulose of highviscosity or of low viscosity, or may use mixtures of these. Also, it ispossible to use scrap celluloid and other nitrocellulose waste orproducts which may not'be'suited for other purposes,'as for example, tomake smokeless powder. Since a floor covering contains nitrocellulosedistributed through a large amount of filler, and since it is possibleto have in such filler an abundance of antacid material such as zincoxide, chalk, magnesium oxide, magnesium carbonate, and the like,nitrocellulose that might be considered dangerous if used in somedirections is available for making floor coverings. There is thereforean outlet for low grade cellulose for the present purpose. Nitrated woodand other analogous nitrocelluloses may be used in whole or in part.Preferably I employ celluloid nitrocellulose, or what is termedcelluloid cotton as the binding agent. This has great toughness and aviscosity which is desirable in some sheeting operations. The viscosityreckoned in terms of lacquer viscosity is approximately 25. or seconds,or may be higher, for example, seconds. Nitrocellulosehaving a-viscosityof 4 or 5 seconds also may, be used.

With the celluloid cotton or nitrocellulose 1 preferably employ aplasticizer such as dibutyl or diamyl phthalate, acetin, triphenyl andtricresyl phosphates. The tricresyl I phosphate is especially desirableas a plasticizer because of its tendency to gender nitrocellulose slowburning. By incorporating a s uflicient amount of the tricresylphosphate along with a substantial proportion of mineral tiller andpossibly using some chlorinated hydrocarbon to saturate the paperbacking a relatively and notably fire resistant .fioor covering may beobtained.

Ill)

Castor. oil or rapeseed oil, preferably of I the blown type, sometimesmay be added to the composition to yield greater flexibility.

A floor covering or rug which flattens effectively is obtained desirablyby incorporation with the celluloid cotton or other nitrocellulose of aquantity of an appropriate resin, one which 18 compat ble withnitrocellulose. A series of resins have been described by main copendingapplications,

as for example, in Serial Nos. 149,528, 150,387, 142,532 and 144,647.Appropriate resins are those made'b-y reacting glycerine or glycol withvarious crystalline organic acids or anhydrides such as phthalic, orsuccinic and with a free fatty acid of glyceride oils, as for example,the fatty "acid of cotton seed oil. In application, Serial -No. 142,532,compositions are claimed which inters and protecting resins,particularly those of the oil acid type. In application, Serial No.144,647, the claims are directed to resins and process of making suchresins by the use of distilled or heat treated fatty acids. InSerial'No. 149,528, the claims are directed to floor coverings includingnitrocellulose tread layers containing wax as well as print ed designsor figured coatings of that char- ,acter, and also burnished coatings.In Serial No. 150,387 the claims are directed to 'the use of wax papercores or otherwise waterproofed paper cores containing or carryingnitrocellulose tread, particularly the sheeted tread, and also toprocesses of sheeting such compositions upon the stated paper cores.

The glycol resins of this character are quite soft-and have someplasticizing effect.

Most natural resins shorten the life of nitrocellulose coatings,whereas, the resins aforesaid act aspreservatives. However, I do notwish to exclude additions of natural resins or of various natural resinswhich have been modified by chemical treatment, as for example, rosinester.

The above resins which have the compatible properties noted may be addedin considerable proportion to assist in obtaining a non-curling rug. Byemploying a goodly proportion of plasticizing material and softcompatible synthetic resin, the desired flattening effect may besecured.

As pigment there may be used for white sheeting such substances aslithopone, zinc oxide, white lead sublimed lead, lead sulphate, barytes,chalk, and the like. Titanoxv is also astrong white, but is not wholly apure white, and in'some cases has been observed to have an action onnitrocellulose. Some of the pigments have an antacid effect which isdesirable. Colors or pigments are added to tint as desired.

Certain mineral substances such as calclum sulphate containing themaximum.

amount of water of hydration are desirable as fillers because they tendto reduce the infiammability in a very marked way.

In addition to the mineral antacids I may use organic antacids such asurea or amines.

The character of the fibrous material employed as filler is important ason this to a certain extent depends the strength and flexibility of thetread and its cushioning ef-- fect. Asbestos fibre, \ground wood,sulphite pulp, and the like, may be used, according to the character ofthe floor covering desired. When a cream colored finish or darker effectis wanted, ground cork of a fineness passing say 60-80 mesh is useful.

For a white textured effect a considerable proportion of cotton flock,linters, bleached sulphite pulp, and the like, may be used.

The greater the proportion of material such as cotton flock, employed,the more textured, as a rule, will be the surface. In pass ing throughthe rolls the cotton flock gathers to some extent and sets irregularly,giving a wavy, rippled or flow-marked surface or what may be termed insome cases, an elephants hide effect.

Suflicient nitrocellulose and pigment to fill in around the fibres ofsuch textured surface and not afford crevices for dirt to lodge in isdesirable as floor coverings even of the textured type should have asurface capable of being cleaned readily.

A solvent frequently is required in rendering the nitrocellulose comosition sufliciently plastic to be smoothly or adequately sheeted andsuch solvents may be those which are known as high-boiling in thelacquer industry, as for example, primary and secondary butyl and amylalcohol and their acetates,

diacetone, alcohol, ethyl-lactate, butyl propionate, and so forth. Usingthese high-boilwith some of the high boiling solvents. This is sometimesadvantageous in securing a good sheetin effect. Methyl acetone also maybe used, li ewise, methyl and ethyl acetate. Isop ropyl acetate is notas powerful a solvent, but may be used to advantage as it is fairlycheap. Associated with the nitrocellulose solvents may be variousdiluents for the sake of cheapness, as for example, benzol and toluol,light petroleum benzine, monochlorobenzol, and the like.

However, the employment of such cheap hi hly volatile solvents bringswith it the difiiculty that the masses of material on hand in theworkroom dry out too quickly, besides giving off a large amount ofvapors which pollute the air. To obtain a workable com position whichremains plastic for an indefinite period, I introduce a small amount ofa mineral wax, as for example, ceresin or paraffin wax. This gives tothe composition two very useful qualities. In the first place, it doesnot dry out quickly at room temperature, but remains plastic 'andworkable for a relaout very quickly at temperatures above. say,

F. Thus, it becomes possible to dry and sheet the composition veryrapidly. This is not true with some of the high boiling solventsmentioned, these requiring more protracted heating, and even so, theodor sometimes is retained ina thick composition for a long time and maybe identified even after the finished rugs have been kept for or shellacwax, may be added, in some cases.

Hot calendering enables a more polished surfaceto be obtained whendesired.

Sometimes it is desirable to have the solvent employed in the plasticmaterial of low inflammability and in such cases I may intro ducenon-inflammable solvents, as for example, carbontetrachloride ortrichlorethylene. The latter is preferable to the former because it isless likely to become acid and also because it may be usedfor dilutionof a nitrocellulose solvent'mixture to greater advanta e.

lin order to secure a non-inflammable plastic a solvent fornitrocellulose should be used which is not too highly inflammable.Acetone and methyl acetate are less suited than ethyl acetate,isop'ropyl. acetate, and some. of the higher esters. Mixtures ofisopropyl acetate or isobutyl acetate with trichlorethylene, whenincorporated with nitrocellulose, filler, plasticizer and'tricresylphosphate, with or without a synthetic resin or preservative solid, willbe found to possess very little, if any, tendency. to inflame onbringing, for example, a lighted match, near a mass of the material. Ifa flame is held in contact with the material for a sufficient length oftimethe solids themselves may take fire, but the rateof combustion. iscomparatively slow and the fire hazard therefore is greatly reduced.Incorporation of wax in such a composition greatly reduces the tendencyto evolution of vapors and this is desirable not. only from thestandpoint of fire hazard, but because the mass of material for sheetingis maintained in a state of uniform plasticity over aconsiderable'period.

In'some cases chlorinated ethylene,,that is, ethylenedichloride, orDutch liquid, may be used to reduce 'infiammability.

While the desirability of using a volatile solvent, that is,quick-drying, after the completion of sheeting has been emphasized,.itshould be understood that I do not exclude sheeting with hot rollswithout solvents, but.

with suflicient plasticizer and/or resin to obtain an adequate softeningeffect. Such hot sheeting cannot be carried'out very satisfactorily withordinary asphalt-saturated felt because the temperature of sheeting isusually higher than the melting point of the saturating material and thelatter is therefore squeezed out of the felt between the rolls.

There are cases also when water emulsions of nitrocellulose andplasticizer may be employed, using for example, bentonite as anemulsifying agent. a

When it is not appropriate to produce a tread of suflicient thickness inone sheeting operation, a tread may be formed, dried and a second layerof tread composition shected on the first, so that there is obtained onetread layer superposed on another. This procedure may be repeated, ifdesired, to obtain a plurality of tread layers.

On the other hand, it is also feasible to sheet first on one side of thepaper support and then to sheet the other side. In this way treadsopposed to one another are obtained and rugs or runners may be made inthis manner which are reversible. When one side has been worn out therug isreversed and a fresh tread surface becomes available. Theseopposed tread layers may, if desired, be of different colors.

- One form of the invention is that in which the rugs, runners,'or otherforms of floor covering take for shipment. To prepare for transportationthe floor covering is rolled so that the flexible sheeting support ofpaper backing is on the inside, while the tread compositionfacesoutwardly, that is, a cross section of the roll would show the tread ofeach spiral or convolution facing outwardly, while the paper supportwould be facing inwardly.

-This, of course, applies to products having the tread on only one sideof the paper backing. By rolling in this manner the tread surface ismaintained in a state of extension, a condition which is highlydesirable, especi'ally in the case ofsurfa-ces of the textured characterdescribed. Rolling such rugs with thetread facing inwardly places thetread surface under compression and tends to affect its texturedcharacter. Hence,- one form of the invention is concerned with a floorcovering in roll form comprising a flexible sheeted support carrying anitrocellulose tread composition, as for example, one having a texturedsurface; said roll having the tread composition facing outwardly,whereby the tread face is maintained in a state of extension.

In accordance with the foregoing there may be obtained a floor coveringsuch as a rug, runner, or strips, latter being intended to be laid inparallel, e. g., to cover a floor stand exposure to such contact withwater as is likely under reasonable service conditions;

paper waterproofed paper, waxed paper,

Wax-sized paper, and the like, carrying a nitrocellulose treadcomposition adapted for underfoot usage; such floor covering preferablyhaving an ornamental surface secured by the use of pleasing'colors,variegated colors, textured finish, andthe like.

A textured effect such as is obtained b embossing a design by means ofrolls is not as satisfactory as the method of destroying the smoothcontinuity of the surface to obtain an irregular reflection of light bysheeting material containing fibrous masses which are somewhat lumpy andwhich on passing through the sheeting rolls form the rough surfacenoted. The employment of emboss ing rolls, however, is not precluded insome cases. I

In one form of the invention, a volatile solvent, or water, is presentin the plastic tread composition and after sheeting this on a support,the product is rapidly heated to cause bubbles or pores to form. Whenthis has progressed sufficiently the sheet may be re-rolled to smoothout the surface somewhat. A more cushiony effect is obtained in thisway. The combined effect of this with aresilient filler such as Woodflour or ground cork is advantageous from the cushioning standpoint.

Another filling material which may be used to good advantage in making amore fire resistant product is vegetable ivory waste. This materialinthe form of fine fragments or dust is a by-product of the manufactureof buttons, and the like. It does not have the same combustibility as,for example, wood flour. Being very light in color it is used to goodadvantage in making white floor cover ing or light-colored andvariegated products.

, waterproofing agents.

When paper is used as the backing material, in addition to impregnatingit with ammonium phosphate and incorporating, for example,-paraflin waxas a waterproofing agent, I may also use chlorinated naphthalene such asthe tetra or penta chloride of naphthalene, perchlorinated benzol,chlorinated asphalt, and the like, as sizing or These chlorinatedcompounds confer fireproof qualities as well as acting as waterproofingagents. In addition, chlorinated naphthalene, and the hke, may beincorporated in the tread composition as a polishing agent and also todepress combustibility.

A feature of my invention is the employment of mineral salts containingwater of;

crystallization or hydration. A salt which is suitable for the purposeis finely-ground or precipitated calcium sulphate containing 2'molecules water. If plaster of Paris, that is, calcined calciumsulphate, is moistened with water, ,it gives up morejthan 2 moleculeswater and this perhydrated' sulphate is a useful filler to employ inmaking tread compositions. In order to obtain fire resistance to a highdegree I preferably employ a sub.- stantial proportion of theperhydrated calcium sulphate.

In some cases nitrocellulose, as for example, celluloid stock, may beused wet with water. This avoids drying the nitrocellulose prior to useand enables it to be stored safely and to be handled with a considerabledegree of impunity. In using such material, if desired, a portion of thewater may be absorbed by mixing calcined calcium sulphate, e. g.,plaster of Paris, when this hydrated Water is absorbed from thenitrocellulose and dries it to the extent corresponding to the amount ofplaster of Paris added. It is important to avoid mixing the plaster ofParis in such a manner that the nitrocellulose mass becomes heated to anobjectionable degree due to the reaction of hydration.

When wet nitrocellulose is employed and all the water is notabsorbedby'a dehydrating filler, the nitrocellulose may be converted into a kindof an emulsionwith plasticizer and posslbly a solvent such as butylacetate or amyl acetate not miscible with water. Ad'- dltional water maybe added if desiredin order that a putty-like material results when thebulky filler is added. In other words, the water serves to replace avolatile solvent in whole or 1n part, to produce the puttylike sheetingcomposition.

When triphenyl or tricresyl phosphate is used as a plasticizer fornitrocellulose in tread compositions which are white or lightcolored,the employment of zinc oxide or cer- I colored or pure white tread.Plasticizers which do not have anydiscoloring action or pigments andantacids which do not have a sapomfying action on triphenyl phosphate ortricresyl phosphate may be used. form of the invention I contemplate forexample,'tricresyl phosphate as the principal plasticizer with pigments,fillers or antacids inert or innocuous thereto. Likewise, when synthetic,resins such as those of the gelpceride type mentioned above are employpreferably a basic pigment is avoid- In one using,

ed which will saponify the resin and cause hardening or brittleness.Hence I prefer to employ pigments, fillers and antacids substantiallyfree from destructive or harden ing action on these resins.

From the foregoing it will appear that I preferably employ in treadcompositions containing nitrocellulose with both syntheticresins andplasticizing agents, a type of pigment, fillers and antacids which areinert with respect to such essential substances, or, at least, have noobjectionable action. Just as I prefer to employ a synthetic resincompatible with nitrocellulose, so I prefer to employ pigments, fillersand antacids which are compatible with nitrocellulose, synthetic used. 5parts of paraffin wax also were'incoreluding paper.

porated to renderthe composition: slow drying at room temperature.

- The materials were thoroughly incorporated, makin a white putty, whichwas sheeted on varlous forms of backing, in-

After sheeting the -moist sheeted product was dried at about C. Thesolvent was rapidly removed at this temperature.

A textured efiect' of a very marked type was obtained by formingfragments of tread composition still plastic but dried out somewhat andapplying such fragments helter skelter to a freshly sheeted surface,then passing through rolls. The somewhat harder lumps of the drier treadcomposition im-- parted a notable texture to the surface in this manner.

' Another tread composition was made from 500 parts by weight ofnitrocellulose, dry" weight, (moistened with denatured alcoh 665parts'plasticizer, 400 parts acetone, and 300 parts benzol.Thenitrocellulose was allowed to soak over night in the solvents andplasticizers and thoroughly mixed the following morning in aWerner-Pfleiderer mixer. There was added 750 parts cork dust,

mesh, 750 partslithopone, 50 partschrome green. The'composition alsoincluded 12 A; partsceresin wax. Finally, 200 parts each of acetone andbenzol were. added to obtain a more plastic putty. v

Large sheets of blotting paper, manilla paper and saturated felt basewere sheeted with this composition and dried at about 45 C. When dryinghad progressed sufiiciently a second'sheeting of material was applied tothe first. Good surfaces were obtained. Some of the samples were placedin a hydraulic press .in contact with a polished sheet of metal and werepressed for five minutes at 500 to 1000 lbs. pressure, the press beingheated by steam at 20 lbs. pressure. This gave a very smooth surface.

In the foregoing formula it should be noted that the plasticizer isdibutyl phthalate, or a mixture of this substance and tricresylphosphate. Or, if more fireproof results are desired, the plasticizermay be entirely tricresyl phosphate.

Variegated results are obtained, for example, by sheeting thelight-colored composition set forth above and applying to the surface atirregular distances small portions of the green composition set forth inthe second formula. In this manner atwo-color or mottled and streakedeffect is secured.

In the form of the invention shown in the drawing, a floor covering isshown in cross section, the flexible sheet support being shown at '1,with the adherent, color variegated tread at 2. I

Still another composition was prepared from:

7 Parts by Q weight Celluloid nitrocellulose 400 Denatured alcohol 160Tricresylphosphate 612 Acetone r 320 Benzol 240 Paraifin wax 20 Urea 4Cottonseed fatty acid phthalio glyceride resin dissolved in an equalweight of Volatile solvent (200 parts actual resin) After thoroughincorporation the following fillers were added:

Parts Cotton flock Finely-divided vegetable ivory 400Per-hydratedcaloium sulphate L00 Lithopone 200 This produced a whitemix. A good yellow tone was obtained by adding 20 parts were obtainedwith saturated felt as a cushioning support.

A- lossysmooth finish was obtained by pressing the dry sheeted productbetween polished metal plates in a hydraulic press at Water.

1000 lbs. pressure per squarefinch and ata temperature corresponding to20 lbs. steam pressure. In one case blotting paper was saturatedwith asolution made from 1 part by weight diam'monium hydrogen phosphate in 2parts The paper then was dried and some of the last mentioned treadcomposition .was sheeted thereon to form a floor covering product. Thismaterial could: not be ignited by the flame of a match. 1

Finally I wish: to emphasize the feature that in the preferred =for'mofthe invention the plastic material when prepared for sheeting is notself-supporting in thin layers of the thickness of the intended tread.This is likewise true after sheeting and before elimination of volatilesolvents. Drying, however, causes. a cementation of the-sheeted mass andstrengthening of the tread. The

paper or other support so needful therefore to carry the tread layer inits freshly sheeted condition becomes less important after drying. Theratio of thickness of the tread support to the tread itself variesaccording to requirements. On the one hand thin kraft paper may carry a.thick tread (double-' sheeted) or thick saturated felt may; have merelya veneer of the cellulose ester plastlc. The ratio thus may be greatlyvaried.

; The employment of highly volatile sol} vents permits the sheetingoperation totake place without artificial heat, hence may be carried outat room "temperature; Blistering, due to the evoliition 'of water vaporsfrom th e fillers. an dthe like in hot rolling as well as otherobjectionablefeaturs of hot rolls, is avoided:

Using felt saturated with soft pitch or a sphalt to give pliabilitymakes hot'rollingin sheeting on a veneer o'fnitrocellulos'e treadcomposition amatter of great practical difii- Gu lty, On the other handthe employment calendering.

the latter being present in substantial quantity, and in pressing intothe sheeted surface fragments of plastic tread composition of anothercolor; whereby a color-variegated finish results.

.- 5. Saturated felt veneered on one side with a multi-colored treadcomposition com rising nitrocellulose, a synthetic resin and a Her.

6. A floor covering comprising a flexible sheeting support carrying anitrocellulose tread composition, and having rolled in hard, plastic,multi-colored fragments yielding a textured effect.

7. A process of making a floor covering comprising sheeting anitrocellulose tread composition upon a backin "and rolling thereintohard,.plastic, multi-colored fragments whereby a textured effect isobtained.

8. ,A floorcovering comprising a flexible sheeting support carrying abaked nitrocellulose tread composition, imparting to the surface aglossy, smooth finish. 9. In the process of making floor covers ingscomprising a nitrocellulose tread composition sheeted upon a flexiblepaper back ing, the .step of hot pressing the sheeted material to givethe treadcomposition a smooth, glossy finish.

10. In the manufacture of floor coverings consisting of a supportcarrying a tread ve neer containing nitrocellulose,-the step whichcomprises sheeting a solvent containing nitrocellulose plasticcomposition onto the tread support, drying and subsequently hot'OARLETON Ennis.

of hi'ghly volatile solvents anchored at room temperaturein a-tread.composition by war; and readily released at slightly higher temperaturesenables such veneer to.be applied qi1ickly-and-cheaply.--

vents and "wax a remarkably adherent tread results even to a paperbacking containing a very considerable proportion "of waxwateriproofing.

What I claim is .1. As a" floor cbverin'ga waterproofedflexible'sheetingsupport carrying a'she'eted nitrocellulose treadcomposition of color-variegated surface; P

2. 'As a floor covering a flexible paper support carrying a sheetednitrocellulose tread composition of multi-colored surface.

3. As a floor covering a flexible wax-containing paper support carryin anitrocellusurface. y I

- lose tread composition of co or-variegated Also, I wish to note that a

